#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include "DHTesp.h"

#define PIN_TRIG 16
#define PIN_ECHO 19
#define ON_LED 5
#define ALERT_LED 18
#define TANK_HEIGHT_CM 300 // Total height of the tank in cm
#define BUZZER_ALARM 13
#define BUZZER_DURATION_MS 30000 // Duration to keep the buzzer on (30 seconds)

// Use the correct address here (0x27 or 0x3F)
LiquidCrystal_I2C lcd(0x27, 16, 2);

const int DHT_PIN = 17;

DHTesp dhtSensor;

unsigned long buzzerStartTime = 0; // Variable to store the time when the buzzer was turned on
bool buzzerActive = false; // To track the buzzer state

void setup() {
  Serial.begin(115200);

  pinMode(PIN_TRIG, OUTPUT);
  pinMode(PIN_ECHO, INPUT);
  pinMode(ON_LED, OUTPUT);
  pinMode(ALERT_LED, OUTPUT);
  pinMode(BUZZER_ALARM, OUTPUT);

  digitalWrite(ON_LED, HIGH); // Ensure ON_LED is always on
  digitalWrite(ALERT_LED, LOW); // Ensure ALERT_LED is initially off
  digitalWrite(BUZZER_ALARM, LOW); // Ensure Buzzer is initially off

  dhtSensor.setup(DHT_PIN, DHTesp::DHT22);

  lcd.init(); // Initialize the LCD
  lcd.backlight(); // Turn on the backlight

  displayInitialMessage();
}

void displayInitialMessage() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("WATER LEVEL");
  lcd.setCursor(0, 1);
  lcd.print("MEASUREMENT");
  delay(3000); // Display for 3 seconds
}

void triggerMeasurement() {
  digitalWrite(PIN_TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(PIN_TRIG, LOW);
}

int readDistance() {
  int duration = pulseIn(PIN_ECHO, HIGH);
  return duration / 58; // Convert duration to distance in cm
}

int calculateWaterLevel(int distanceCM) {
  return TANK_HEIGHT_CM - distanceCM; // Calculate water level
}

void handleCriticalLowLevel() {
  digitalWrite(ALERT_LED, HIGH); // Turn on ALERT_LED
  digitalWrite(BUZZER_ALARM, HIGH); // Turn on Buzzer
  tone(BUZZER_ALARM, 1000); // Generate a tone of 1000 Hz
  buzzerStartTime = millis(); // Record the time when the buzzer was turned on
  buzzerActive = true; // Set buzzer as active
}

void handleWarningLevel() {
  digitalWrite(ALERT_LED, HIGH); // Turn on ALERT_LED
  delay(500);  // ON for 0.5 seconds
  digitalWrite(ALERT_LED, LOW);  // Turn off ALERT_LED
  digitalWrite(BUZZER_ALARM, LOW); // Turn off Buzzer
  noTone(BUZZER_ALARM); // Ensure Buzzer is off
  buzzerActive = false; // Set buzzer as inactive
  delay(1500); // OFF for 1.5 seconds
}

void handleNormalLevel() {
  digitalWrite(ALERT_LED, LOW);  // Ensure ALERT_LED is off
  digitalWrite(BUZZER_ALARM, LOW); // Ensure Buzzer is off
  noTone(BUZZER_ALARM); // Ensure Buzzer is off
  buzzerActive = false; // Set buzzer as inactive
}

void checkBuzzer() {
  if (buzzerActive && (millis() - buzzerStartTime >= BUZZER_DURATION_MS)) { // Duration to keep buzzer on
    noTone(BUZZER_ALARM); // Turn off the Buzzer
    buzzerActive = false; // Set buzzer as inactive
  }
}

String getWaterLevelStatus(int waterLevel) {
  if (waterLevel <= 60) { // Critical low level
    return "CRITICAL";
  } else if (waterLevel <= 150) { // Warning level
    return "WARNING";
  } else {
    return "NORMAL";
  }
}

String getTemperatureStatus(float temperature) {
  if (temperature < 5.0 || temperature > 45.0) {
    return "WARNING";
  } else {
    return "NORMAL";
  }
}

String getHumidityStatus(float humidity) {
  if (humidity < 20.0 || humidity > 80.0) {
    return "WARNING";
  } else {
    return "NORMAL";
  }
}

void displayWaterLevel(int waterLevel) {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("WaterLvl: ");
  lcd.print(waterLevel);
  lcd.print("cm");
  lcd.setCursor(0, 1);
  lcd.print("Status: ");
  lcd.print(getWaterLevelStatus(waterLevel));
  delay(2000); // Wait 2 seconds
}

void displayTemperature(float temperature) {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(temperature, 1);
  lcd.print("°C");
  lcd.setCursor(0, 1);
  lcd.print("Status: ");
  lcd.print(getTemperatureStatus(temperature));
  delay(2000); // Wait 2 seconds
}

void displayHumidity(float humidity) {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Hum: ");
  lcd.print(humidity, 1);
  lcd.print(" %RH");
  lcd.setCursor(0, 1);
  lcd.print("Status: ");
  lcd.print(getHumidityStatus(humidity));
  delay(2000); // Wait 2 seconds
}

void loop() {
  triggerMeasurement();
  int distanceCM = readDistance();
  int waterLevel = calculateWaterLevel(distanceCM);

  // Read temperature and humidity
  TempAndHumidity data = dhtSensor.getTempAndHumidity();
  float temperature = data.temperature;
  float humidity = data.humidity;

  // Display Water Level
  displayWaterLevel(waterLevel);

  // Display Temperature
  displayTemperature(temperature);

  // Display Humidity
  displayHumidity(humidity);

  // Handle alarm and LED
  if (waterLevel <= 60) { // Critical low level
    handleCriticalLowLevel();
  } else if (waterLevel <= 150) { // Warning level
    handleWarningLevel();
  } else {
    handleNormalLevel();
  }
  
  checkBuzzer();
 // delay(2000); // Delay before the next cycle
}